What Medicare Advantage Is and How It Differs from Original Medicare

Medicare Advantage (also called Part C) is an alternative way to receive your Medicare benefits. Instead of using Original Medicare (Part A and Part B), you enroll in a private insurance plan that contracts with Medicare. The plan must cover everything Original Medicare covers — hospital stays, doctor visits, and medical equipment — but it can do so with different costs, networks, and rules.

The main difference: Original Medicare lets you see any doctor or hospital that accepts Medicare. Medicare Advantage plans typically require you to use doctors and hospitals in their network, except in emergencies. Some plans also include prescription drug coverage (Part D) built in, while Original Medicare requires a separate Part D plan.

Medicare Advantage plans are run by insurance companies like UnitedHealth, Humana, Anthem, and Aetna. Each plan sets its own copays, deductibles, and out-of-pocket limits. You still pay your Part B premium to Medicare, plus a premium to the insurance company (which may be zero dollars).

Key Takeaways

  • Medicare Advantage plans are private insurance alternatives to Original Medicare that must cover the same basic services but often include prescription drug coverage and dental or vision benefits.
  • You must use in-network doctors and hospitals in most plans, and you cannot use your Medicare card to see out-of-network providers except in emergencies.
  • Plans vary widely in cost, deductibles, and copays — a $0 premium plan in one county may not exist in another, and costs change every year.
  • You can switch plans or return to Original Medicare during the Annual Enrollment Period (October 15 to December 7) or if you have a may have access to life event.
  • If you switch to Original Medicare after being in Advantage, you may need to enroll in a separate Part D plan and may face higher premiums if you wait.

Types of Medicare Advantage Plans and What Each Covers

The most common type is a Health Maintenance Organization (HMO) plan. You choose a primary care doctor who coordinates your care and must refer you to specialists. You can only see in-network providers except in emergencies. Copays are usually low, but your out-of-pocket costs are capped.

A Preferred Provider Organization (PPO) plan gives you more flexibility. You can see any doctor without a referral, but in-network doctors cost less. Out-of-network care costs more but is still covered. PPO plans typically have higher premiums and deductibles than HMOs.

Private Fee-for-Service (PFFS) plans let you see any doctor who accepts the plan's payment terms — you do not need a referral. These are less common and may have higher out-of-pocket costs. Special Needs Plans (SNPs) are designed for people with specific conditions (like diabetes or heart disease) or who live in institutions. They have more limited networks but may offer extra benefits tailored to your condition.

Most plans now include prescription drug coverage, dental benefits (usually cleanings and exams, not major work), vision (eye exams and glasses or contacts), and hearing aids. The scope and cost of these extras vary by plan and region.

Costs You Will Pay: Premiums, Deductibles, and Out-of-Pocket Limits

You pay three types of costs in a Medicare Advantage plan. First, your Part B premium goes to Medicare (currently $164.90 per month for most people in 2024, but this changes yearly). Second, you may pay a plan premium to the insurance company — this can be $0, or it can be $100 or more per month depending on the plan and your location. Third, you pay copays and coinsurance when you use care: typically $10 to $50 per doctor visit, $250 to $500 per hospital stay, and varying amounts for prescriptions.

Every Medicare Advantage plan has an out-of-pocket maximum. Once you reach it in a calendar year, the plan pays 100% of covered services for the rest of that year. This maximum is set by Medicare and varies, but in 2024 it cannot exceed $7,550 for in-network care in most plans. This is a safety net — it means your costs have a ceiling.

Prescription drug costs depend on the plan's formulary (the list of covered drugs) and your drug tier. A generic drug might cost $5 per month, while a brand-name drug might cost $50 or more. Some plans have a coverage gap (the "donut hole") where you pay more after spending a certain amount, though this gap is smaller than it used to be.

Costs change every January. A plan you paid $0 premium for in 2024 might cost $25 per month in 2025. Your copays and deductibles also change. You receive a notice in October showing your plan's 2025 costs, which is when you can decide to switch.

How to Enroll in a Medicare Advantage Plan

You can enroll during your Initial Enrollment Period, which is the three months before, during, and after the month you turn 65. You can also enroll during the Annual Enrollment Period (October 15 to December 7 each year), when your coverage starts January 1. If you miss these windows, you can only enroll if you have a may have access to life event — losing employer coverage, moving out of your plan's service area, or certain other changes — within 60 days of the event.

To enroll, you can visit Medicare.gov, call 1-800-MEDICARE, or work with a licensed insurance agent. Medicare.gov has a plan comparison tool where you enter your zip code and current doctors and medications. The tool shows you plans available in your area, their costs, and whether your doctors are in-network. This is the fastest way to compare.

You will need your Social Security number and information about your current coverage. If you are switching from Original Medicare, you do not need to do anything to drop it — enrolling in Advantage automatically ends your Original Medicare. If you are switching from one Advantage plan to another, the new plan takes over on January 1 and the old one ends.

If you receive Medicaid (state health insurance for low income), you may have extra protections. Some states require plans to notify you before your coverage changes, and you may have the right to switch plans more often. Ask your state Medicaid office about your rights.

Network Restrictions and Out-of-Network Care

In an HMO plan, you must use in-network doctors and hospitals. If you see an out-of-network provider without a referral or emergency, the plan does not pay and you may owe the full bill. The exception is emergency care — if you have a heart attack or serious injury, any hospital must treat you and your plan will pay. Urgent care (like a broken bone on a weekend) is also covered out-of-network if in-network care is not available.

In a PPO plan, you can see any doctor, but in-network costs less. You might pay a $20 copay for an in-network visit and $50 plus 20% coinsurance for an out-of-network visit. The out-of-network provider can bill you for the difference between what they charge and what the plan pays, though this is limited.

Before you enroll, check whether your current doctors are in the plan's network. Medicare.gov's plan comparison tool shows this. Call your doctor's office directly to confirm — sometimes the plan's website is out of date. If your doctor leaves the network after you enroll, the plan usually gives you time to find a new doctor or may let you continue seeing them at in-network rates for a transition period.

Switching Plans or Returning to Original Medicare

You can switch to a different Medicare Advantage plan or return to Original Medicare during the Annual Enrollment Period (October 15 to December 7). The change takes effect January 1. You can also switch if you have a may have access to life event — moving, losing coverage, or a change in your health or family situation — within 60 days of the event.

If you return to Original Medicare after being in Advantage, you should enroll in a Part D prescription drug plan at the same time. If you wait, you may pay a higher premium for Part D later because of a late enrollment penalty. The penalty is 1% of the national average Part D premium for each month you were without coverage, and it is permanent.

You also lose any supplemental coverage (Medigap) you had before. If you want Medigap after leaving Advantage, you may have to go through medical underwriting and may be denied or charged more if you have health conditions. Some states have protections that let you buy Medigap without underwriting if you return to Original Medicare within a certain window, so check your state's rules.

Common Mistakes and How to Avoid Them

The biggest mistake is not comparing plans every year. Your current plan's costs may rise sharply, or a better plan may become available. Spend 20 minutes in October comparing your options on Medicare.gov. You might save hundreds of dollars by switching.

Another mistake is assuming your doctor is in-network without checking. Plans update their networks, and doctors move or drop out. Call your doctor's office in October to confirm they are still in your plan for the coming year. If they are not, ask whether they plan to rejoin or whether you should switch plans.

Do not wait to enroll in Part D if you switch back to Original Medicare. Enroll during the same enrollment period you use to leave Advantage. If you miss the important date, you will pay a penalty on top of your Part D premium for as long as you have Part D.

Finally, do not assume a $0 premium plan is the best deal. A plan with no premium might have high copays or a narrow network. Compare total costs — premium plus copays for the care you actually use — not just the premium.

Frequently Asked Questions

Can I use my Medicare card at any hospital if I am in a Medicare Advantage plan?

No. Your Medicare card is still valid, but it does not may provide coverage. You must use in-network hospitals in an HMO plan. In a PPO, you can use any hospital, but out-of-network hospitals cost more. Always call ahead to confirm the hospital is in-network before you go, or use the plan's website to check.

What happens to my Medicare Advantage plan if I move to a different state?

Your plan likely will not work in the new state because plans are regional. You will need to enroll in a new plan in your new location. Moving is a may have access to life event, so you can enroll outside the Annual Enrollment Period. Contact your plan and Medicare to start the process at least 30 days before you move.

Do I still have to pay my Part B premium if I am in Medicare Advantage?

Yes. You pay your Part B premium to Medicare no matter which type of Medicare you choose. Some Medicare Advantage plans have a $0 plan premium on top of that, but your Part B premium is separate and required.

Can I go back to Original Medicare if I do not like my Medicare Advantage plan?

Yes, during the Annual Enrollment Period (October 15 to December 7) or if you have a may have access to life event. If you switch back, enroll in a Part D plan at the same time to avoid a late enrollment penalty. You may also want to look into Medigap coverage, though you may face higher costs or medical underwriting depending on your state.

What if my plan drops out of Medicare or leaves my area?

Your plan must notify you by October 31 if it is leaving. You then have until December 7 to switch to a different plan or return to Original Medicare without penalty. This is treated as a may have access to event, so you can enroll outside the normal enrollment period. Medicare will send you a list of plans still available in your area.